U.S. patent application number 11/865996 was filed with the patent office on 2008-04-03 for vehicle fleet security system.
Invention is credited to Marc-Andre BELIVEAU, Robert BLANCHET.
Application Number | 20080079551 11/865996 |
Document ID | / |
Family ID | 39260554 |
Filed Date | 2008-04-03 |
United States Patent
Application |
20080079551 |
Kind Code |
A1 |
BLANCHET; Robert ; et
al. |
April 3, 2008 |
VEHICLE FLEET SECURITY SYSTEM
Abstract
The invention relates to a fleet security system comprising a
vehicle security unit (VSU) to be installed inside each vehicle, on
the sun visor or on the dashboard of the vehicle, and connected to
the vehicle using the On-Board Diagnostics (OBD) connector of the
vehicle. An authorized user holds the key of the vehicle to be used
and an electronic security key. When the authorized user opens the
door of the vehicle, the VSU detects a disturbance in the vehicle
and wirelessly sends a disturbance event message to a fleet master
unit. The authorized user then has a given deactivation time period
(such as thirteen seconds) to show its security key to a key reader
located inside the vehicle, on the VSU. The security key code is
validated by the master unit which will command the VSU to disarm
its disturbance detection.
Inventors: |
BLANCHET; Robert; (Quebec,
CA) ; BELIVEAU; Marc-Andre; (Saint-Jerome,
CA) |
Correspondence
Address: |
OGILVY RENAULT LLP
1981 MCGILL COLLEGE AVENUE, SUITE 1600
MONTREAL
QC
H3A2Y3
US
|
Family ID: |
39260554 |
Appl. No.: |
11/865996 |
Filed: |
October 2, 2007 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
60848635 |
Oct 3, 2006 |
|
|
|
Current U.S.
Class: |
340/426.1 |
Current CPC
Class: |
B60R 25/102 20130101;
G08G 1/20 20130101; B60R 25/1004 20130101 |
Class at
Publication: |
340/426.1 |
International
Class: |
B60R 25/10 20060101
B60R025/10 |
Claims
1. A vehicle security unit for installation inside a vehicle of a
fleet of vehicles and in wireless communication with a master unit,
said vehicle being associated with a vehicle identification code,
the vehicle security unit comprising: an armed mode to be active or
inactive; a disturbance event detection system for detecting a
disturbance event associated with said vehicle; a security key
reader for reading a security key, and for producing a security key
reading event in response to the reading, said security key having
a key identification code; a vehicle transmitter for transmitting a
disturbance event message to said master unit in response to said
disturbance event if said security mode is active and for
transmitting a security key event message to said master unit in
response to said security key reading event, said disturbance event
message and said security key event message comprising said vehicle
identification code and said security key event message comprising
said key identification; and a receiver for receiving a command
from said master unit to deactivate said armed mode.
2. The vehicle security unit as claimed in claim 1, wherein said
vehicle has an on-board diagnostic connector and a battery wherein
said vehicle security unit has an on-board diagnostic input to be
connected to said on-board diagnostic connector for detecting at
least a voltage drop event in said battery, said disturbance event
comprising said voltage drop event.
3. The security system as claimed in claim 2, wherein said on-board
diagnostic input is further for powering said vehicle security unit
using said battery.
4. The security system as claimed in claim 2, wherein said vehicle
security unit is installed in the passenger compartment of said
vehicle and wherein said vehicle security unit is electrically
connected to said vehicle using only said on-board diagnostic
connector.
5. A security system for a fleet of vehicles, said security system
comprising: a vehicle security unit for installation inside a
passenger compartment of at least one of said vehicles, each one of
said vehicles being associated with a vehicle identification code,
each vehicle security unit having: an armed mode to be active or
inactive; a disturbance event detection system for detecting a
disturbance event associated with said vehicle; a security key
reader for reading a security key, and for producing a security key
reading event in response to the reading, said security key having
a key identification code; a vehicle transceiver for transmitting a
disturbance event message in response to said disturbance event if
said security mode is active and for transmitting a security key
event message in response to said security key reading event, said
disturbance event message and said security key event message
comprising said vehicle identification code and said security key
event message comprising said key identification, and for receiving
a command to deactivate said armed mode; and a master unit in
wireless communication with said vehicle security unit, said master
unit having: a master transceiver for receiving said disturbance
event message and said security key event message, and for sending
said command to said vehicle security unit; a processing module in
communication with said master transceiver and for validating said
security key identification code when receiving a security key
event message, for determining said command to deactivate said
armed mode if said identification code is valid, said command to be
sent using said master transceiver, and for activating an alarm
flag when receiving said disturbance event message a predetermined
deactivation time period following the receiving if said armed mode
is active.
6. The security system as claimed in claim 5, wherein said vehicle
has an on-board diagnostic connector and a battery wherein said
vehicle security unit has an on-board diagnostic input to be
connected to said on-board diagnostic connector for detecting at
least a voltage drop event in said battery, said disturbance event
comprising said voltage drop event.
7. The security system as claimed in claim 6, wherein said on-board
diagnostic input is further for powering said vehicle security unit
using said battery.
8. The security system as claimed in claim 5, wherein said master
transceiver is further for transmitting an acknowledgement message
to said vehicle security unit when receiving at least one of said
disturbance event message and said security key event message and
wherein said vehicle transceiver is further for receiving said
acknowledgement message and for deactivating a message transmission
mode when no acknowledgement message is received for a number of
consecutive times.
9. A vehicle security unit for installation in a vehicle of a fleet
of vehicles and in wireless communication with a master unit, said
vehicle being associated with a vehicle identification code and
having an on-board diagnostic connector and a battery, said vehicle
security unit comprising: a disturbance event detection system for
detecting a disturbance event associated with said vehicle and
comprising an on-board diagnostic input to be connected to said
on-board diagnostic connector for detecting at least a voltage drop
event in said battery, said disturbance event comprising said
voltage drop event; a security key reader for reading a security
key, and for producing a security key reading event in response to
the reading, said security key having a key identification code;
and a vehicle transmitter for transmitting a disturbance event
message to said master unit in response to said disturbance event
and for transmitting a security key event message to said master
unit in response to said security key reading event, said
disturbance event message and said security key event message
comprising said vehicle identification code and said security key
event message comprising said key identification.
10. The security system as claimed in claim 9, wherein said
on-board diagnostic input is further for powering said vehicle
security unit using said battery.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 35USC.sctn.119(e) of
U.S. provisional patent application(s) 60/848,635 filed Oct. 3,
2006, the specification(s) of which being hereby incorporated by
reference.
TECHNICAL FIELD
[0002] The invention relates to a security system for a fleet of
vehicles. More particularly, the invention relates to a system for
monitoring activities related to each vehicle of a fleet using a
vehicle security unit installed inside each vehicle and
communicating with a fleet master unit.
BACKGROUND OF THE ART
[0003] A vehicle fleet security system can be used by dealers, car
rental companies, delivery service companies or other entities
having a large number of vehicles to manage, for monitoring,
tracking and controlling access to the vehicles of the fleet, and
for providing an anti-thief security system for their fleet of
vehicles while the vehicles are located in the fleet parking
lot.
[0004] Some fleet security systems use a nearly standalone security
unit installed in each vehicle. Whenever an intrusion event occurs,
the unit activates an alarm on the vehicle, such as an alarm siren,
and also transmits an alarm signal to a base station which sets an
alarm accordingly.
[0005] Other fleet security systems also deal with controlling the
access to the vehicles. For example, a vehicle security unit (VSU)
may be installed outside each vehicle for direct access to it by an
authorized person. The VSU contains the key of its associated
vehicle and the authorized person may obtain the key by presenting
an identification tag to a reader on the VSU. The VSU then opens
the key box so that the authorized person can take the key to
access the vehicle. The security system is typically disarmed
during business hours such that no alarm is generated when an
authorized person enters the vehicle.
[0006] Other fleet security systems use a hidden disarming switch
inside the vehicle such that any person aware of the presence of
the VSU and of the location of the hidden switch can use the
vehicle without activating an alarm.
[0007] Most vehicle security systems require a complex installation
on the vehicle, requiring modifications to the vehicle. A
convenient and easy-to-install fleet security system would
therefore be of interest.
SUMMARY
[0008] The invention relates to a fleet security system comprising
a vehicle security unit (VSU) to be installed inside each vehicle,
such as on the sun visor or on the dashboard of the vehicle, and
connected to the vehicle using the On-Board Diagnostics (OBD)
connector of the vehicle. An authorized user holds the key of the
vehicle to be used and an electronic security key. When the
authorized user opens the door of the vehicle, the VSU detects a
disturbance in the vehicle and wirelessly sends a disturbance event
message to a fleet master unit located in the car dealer building,
for example. The authorized user then has a given deactivation time
period (such as thirteen seconds) to show its security key to a key
reader located inside the vehicle, on the VSU. The security key
code is validated by the master unit which will command the VSU to
disarm its disturbance detection.
[0009] One aspect of the invention provides a vehicle security unit
for installation inside a vehicle of a fleet of vehicles and in
wireless communication with a master unit. The vehicle is
associated with a vehicle identification code. The vehicle security
unit comprises an armed mode to be active or inactive; a
disturbance event detection system for detecting a disturbance
event associated with the vehicle; a security key reader for
reading a security key, and for producing a security key reading
event in response to the reading, the security key having a key
identification code; and a vehicle transmitter for transmitting a
disturbance event message to the master unit in response to the
disturbance event if the security mode is active and for
transmitting a security key event message to the master unit in
response to the security key reading event, the disturbance event
message and the security key event message comprising the vehicle
identification code and the security key event message comprising
the key identification; and a receiver for receiving a command from
the master unit to deactivate the armed mode.
[0010] Another aspect of the invention provides a security system
for a fleet of vehicles. The security system comprises: a vehicle
security unit for installation inside a passenger compartment of at
least one of the vehicles, and a master unit in wireless
communication with the vehicle security unit. Each one of the
vehicles is associated with a vehicle identification code. Each
vehicle security unit has: an armed mode to be active or inactive;
a disturbance event detection system for detecting a disturbance
event associated with the vehicle; a security key reader for
reading a security key, and for producing a security key reading
event in response to the reading, the security key having a key
identification code; and a vehicle transceiver for transmitting a
disturbance event message in response to the disturbance event if
the security mode is active and for transmitting a security key
event message in response to the security key reading event, the
disturbance event message and the security key event message
comprising the vehicle identification code and the security key
event message comprising the key identification, and for receiving
a command to deactivate the armed mode. The master unit has: a
master transceiver for receiving the disturbance event message and
the security key event message, and for sending the command to the
vehicle security unit; a processing module in communication with
the master transceiver and for validating the security key
identification code when receiving a security key event message,
for determining the command to deactivate the armed mode if the
identification code is valid, the command to be sent using the
master transceiver, and for activating an alarm flag when receiving
the disturbance event message a predetermined deactivation time
period following the receiving if the armed mode is active.
[0011] Another aspect of the invention provides a vehicle security
unit for installation in a vehicle of a fleet of vehicles and in
wireless communication with a master unit. The vehicle is
associated with a vehicle identification code and has an on-board
diagnostic connector and a battery. The vehicle security unit
comprises: a disturbance event detection system for detecting a
disturbance event associated with the vehicle and comprising an
on-board diagnostic input to be connected to the on-board
diagnostic connector for detecting at least a voltage drop event in
the battery, the disturbance event comprising the voltage drop
event; a security key reader for reading a security key, and for
producing a security key reading event in response to the reading,
the security key having a key identification code; and a vehicle
transmitter for transmitting a disturbance event message to the
master unit in response to the disturbance event and for
transmitting a security key event message to the master unit in
response to the security key reading event, the disturbance event
message and the security key event message comprising the vehicle
identification code and the security key event message comprising
the key identification.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a schematic of a fleet security system;
[0013] FIG. 2 is a perspective view of a vehicle security unit
(VSU) to be installed in each vehicle of the fleet along with a
security key;
[0014] FIG. 3 is a block diagram of the fleet security system
wherein the basic electronic components are shown;
[0015] FIG. 4 is a block diagram of the VSU wherein the disturbance
detector is exploded;
[0016] FIG. 5 is a flow chart illustrating the behavior of the VSU
upon a reset;
[0017] FIG. 6 is a flow chart illustrating the behavior of the VSU
in a disarmed mode;
[0018] FIG. 7 is a flow chart illustrating the behavior of the VSU
in a maintenance mode;
[0019] FIG. 8 is a flow chart illustrating the behavior of the
master unit upon receiving of an event message from a VSU;
[0020] FIG. 9 is a flow chart illustrating the behavior of the
master unit upon receiving a presence message from a VSU; and
[0021] FIG. 10 is a flow chart illustrating the inventory check
performed by the master unit.
[0022] It will be noted that throughout the appended drawings, like
features are identified by like reference numerals.
DETAILED DESCRIPTION
[0023] The invention provides a fleet security system comprising a
vehicle security unit (VSU) to be installed inside each vehicle,
such as on the sun visor dashboard of the vehicle, and connected to
the vehicle using the On-Board Diagnostics (OBD) connector of the
vehicle. An authorized user holds the key of the vehicle to be used
and an electronic security key. When the authorized user opens the
door of the vehicle, the VSU detects a disturbance in the vehicle
and wirelessly sends a disturbance event message to a fleet master
unit located in the car dealer building, for example. The
authorized user then has a given deactivation time period (such as
thirteen seconds) to show its security key to a key reader located
inside the vehicle, on the VSU. The master unit receives the key
identification code and validates it. If the key identification
code is valid, the master unit sends a command to the VSU to go in
a disarmed mode wherein the disturbance event detector is
deactivated and no event messages are sent to the master unit. When
the authorized person returns the vehicle to the parking lot, he or
she simply locks the doors of the vehicle and the VSU automatically
goes in an armed mode when no disturbance event has occurred for a
given activation time period (such as thirty seconds). The user is
thus not required to arm the security system and an employee thus
cannot make the mistake of forgetting to arm the security
system.
[0024] However, when the vehicle leaves the parking lot, the VSU is
rearmed in the case of inactivity in the vehicle for more than
thirty seconds, i.e. if the authorized person leaves the vehicle
for more then thirty seconds. As it does not have any authority to
disarm itself and as it is out of range of the master unit, the VSU
will then stay in the armed mode. Consequently, the VSU will
transmit all new events detected. As the VSU goes out of reach of
the vehicle, it stops receiving acknowledgements from the fleet
master unit. As a consequence, it retries to send the disturbance
event message for two more times. As an acknowledgement is still
not received, it goes back to the beginning of the armed mode and
will not retry to send this specific event anymore. Furthermore,
when the vehicle re-enters the parking lot, the master unit
recognizes that this specific VSU was deactivated by an authorized
user. The master unit then ignores all events received from this
VSU until it is reactivated after thirty seconds of inactivity.
[0025] In order to keep an up-to-date inventory of the vehicles of
the fleet, each VSU periodically sends a presence message to the
master unit which keeps track of the inventory. Simultaneously,
according to a list of the vehicles that are expected to be in the
fleet (i.e. VSU armed), the master unit checks if all vehicles of
the list are present in the fleet. When no presence message is
received from a vehicle that should be armed for more than a given
missing time period, such as five minutes, the vehicle is
identified as missing and a warning flag is activated. An
administrator is then informed that one vehicle of the fleet is
missing and can access the master unit database to see who was the
last person to use the vehicle for example. He may then contact
this person to see if an unforeseen event occurred. He may also use
the cameras installed in the parking lot or go directly on the spot
to check if the vehicle was stolen for example. An appropriate
action is then carried out accordingly. The VSU may also comprise a
local positioning system (with a covering range of about 5 to 10
km) for locating a missing vehicle in the area around the parking
lot or, alternatively, it may comprise a global positioning system
for covering a larger area.
[0026] Now referring to the drawings, FIG. 1 illustrates a security
system 10 for a fleet of vehicles 12. Each vehicle 12 has a vehicle
security unit (VSU) 14 installed inside the vehicle 12. The VSU 14
is in wireless connection with a master unit 16 typically located
in a building near the parking lot where the vehicles 12 are
parked. The master unit 16 controls the disarming of the VSU 14 for
access to it by authorized users, and generates an alarm flag upon
unauthorized attempts to enter, to lift or to cut the current to
the VSU 14. The generated alarm flag typically switches on an alarm
siren 20 and contacts an administrator or a security guard or
contacts a central monitoring station 18 if the alarm occurred off
business hours. The master unit 16 may optionally be networked with
work stations 22 that can be used for remotely inputting data and
for remotely visualizing alarm flags and historic data regarding
the events associated with each vehicle and stored in a database by
the master unit 16.
[0027] FIG. 2 illustrates a VSU 14 to be installed in a vehicle 12
(not shown). The VSU 14 is a small device to be installed inside
each vehicle of the fleet, on the sun visor or on the dashboard for
example. It may be fixed to the sun visor using rubber bands and
comprises an On-Board Diagnostics (OBD) input connector 38 to be
connected to the vehicle using the OBD output connector of the
vehicle, typically an OBD2 (accessible from the passenger
compartment, under the dashboard). The OBD connection is used to
provide electrical power from the battery of the vehicle, to the
VSU 14. It is also used to monitor the voltage level of the battery
and to eventually detect an ignition of the car or a power
interruption due to, for example, an attempt to disconnect the VSU
14 or the car battery. The VSU 14 also comprises motion detectors
28 for detecting an intrusion in the car. When an intrusion is
detected, e.g. someone opens the door of the vehicle, an authorized
person has a given deactivation time period for showing its
security key 24 to the security key reader 34 located on the VSU
14. If no security key is shown, i.e. there was an unauthorized
intrusion, an alarm is activated by the master unit (not shown).
The VSU 14 also comprises an alarm indicator 42, typically a super
bright light emission diode (LED), used to localize the vehicle
that generated an alarm, among the vehicles of the fleet. The alarm
indicator 42 provides a light sufficiently bright for easily seeing
it a great distance away from the vehicle.
[0028] FIG. 3 illustrates the main components of the fleet security
system 10. The fleet security system 10 comprises a VSU 14
installed in each vehicle 12 of the fleet and in wireless
communication with a master unit 16. Each vehicle 12 has a vehicle
identification code and an OBD output 40. The VSU 14 has a reset
mode, an armed mode, a disarmed mode for using the vehicle, i.e.
driving it out of the parking lot, and a maintenance mode, for
allowing a technician to conduct maintenance of the vehicle 12,
including adding and removing of VSUs. The VSU 14 is electrically
powered using an OBD input 38 connected to the OBD output 40 of the
vehicle 12. The VSU 14 also comprises a disturbance detector for
detecting a disturbance event, such as an intrusion or an attempt
to lift the vehicle, associated with the vehicle 12, and a security
key reader 34 for reading a security key (not shown). Each security
key has a unique key identification code. A key reading produces a
key reading event. The VSU 14 comprises a VSU transmitter/receiver
36 for transmitting messages to the master unit 16 when a
disturbance event or a key reading event occurs and the VSU 14 is
in the armed mode and for receiving commands from the master unit
16. Possible commands include a command to go into the disarmed
mode or the maintenance mode or a command to activate or deactivate
the alarm indicator. Whenever the VSU 14 sends a disturbance event
message, the message includes the type of disturbance event and the
vehicle identification code. The vehicle identification code may be
a code associated with the VSU 14 which the master unit 16
associates with the given vehicle 12 according to a database. A key
reading event comprises the key identification code for validation
by the master unit 16.
[0029] The master unit 16 is typically a computer such as a
workstation comprising a processing unit 46 and a data input 50
such as a keyboard, a floppy drive or a network connection for
adding or removing vehicles in the fleet, for associating the VSU
14 identification code to the vehicle 12, for adding or removing
security keys and for associating each security key identification
code to its user and to a security level. For example, when a
vehicle is sold, the associated VSU 14 can be removed and it can be
associated to another vehicle when a new vehicle is added to the
inventory.
[0030] The processing unit 46 is connected to a master
transmitter/receiver 44 for receiving disturbance event messages
and security key event messages from the VSUs 14 and for sending
commands to the VSUs 14. When receiving an event message, the
processing unit 46 determines the proper action to be undertaken.
For example, when receiving a disturbance event, it waits for a key
reading event. If a key reading event is received, the processing
unit 46 validates the security key identification code and sends a
command to the proper VSU 14 for going into the disarmed mode or
into the maintenance mode, depending on the security level
associated with the security key identification code, as will be
discussed further below. If no key reading event is received after
the given deactivation time period, the processing unit 46
activates an alarm flag.
[0031] Using an alarm output 48, the alarm flag is transmitted to a
central monitoring station and/or to an intercommunication system,
an alarm siren or a pager in order to alert the appropriate person
in charge or the security guard.
[0032] The master unit 16 also typically comprises a listing
database (not shown) for associating each vehicle to a unique
vehicle identification code and each security key identification
code to a unique authorized user, and a logging database (not
shown) for storing each event received for each vehicle 12. The
stored data includes the time at which the event occurred, the
vehicle identification code, the type of event, the security key
identification code in case of a key reading event, etc.
Accordingly, using this database, it is possible to retrieve all
the events associated with a specific vehicle. If a vehicle is
missing, for example, it will be possible to retrieve the last
authorized person that accessed the vehicle.
[0033] FIG. 4 shows the VSU 14 in more details. The disturbance
detector comprises a motion detector 28 for detecting an intrusion
in the vehicle 12, a tilt detector 30 for detecting an attempt to
lift the vehicle, for example, and a voltage drop detector 32 for
detecting an ignition of the car or an attempt to power off the VSU
14. A disturbance event provided by the motion detector 28 is
generally a low level disturbance event while a disturbance event
provided by the tilt detector 28 is generally a high level
disturbance event. The voltage drop detector 32 detects a sudden
drop of voltage. A drop associated with a power off is a high level
disturbance event. The tilt detector 28 detects a tilt exceeding a
threshold, three degrees for example, about any of the four axis of
the vehicle. The VSU 14 is powered by the battery of the vehicle
through the OBD input 40 but it also comprises an energy back-up
source 52, such as a capacitor, for providing a sufficient time of
autonomy for transmitting the disturbance event in case the battery
is disconnected The disturbance detector may also comprise other
detectors such as a device for detecting an attempt to steel a
wheel, an airbag, a navigation system.
[0034] The logic of the VSU comprises four modes of operations: a
reset mode, an armed mode, a disarmed mode and a maintenance mode.
FIG. 5 illustrates the reset mode and the armed mode. When a VSU is
powered on, an initialization process 512 is conducted. Among other
things, the tilt detector is initialized. The duration of the
initialization process is fixed by a first timer, i.e. T1. When the
initialization is completed the VSU goes into the armed mode 514.
In the reset mode, it may be possible to detect key reading
events.
[0035] In the armed mode, when a low level disturbance, such as
motion detection, is detected by the VSU, a disturbance event
message is automatically transmitted to the master unit. An
authorized user than has a predetermined deactivation time period,
typically thirteen seconds, to show its security key to the
security key reader in order to deactivate the armed mode and
prevent the alarm. If no valid key is shown, the master unit will
activate an alarm flag. During business hours, the alarm will
activate an intercommunication system, an alarm siren or a pager to
alert the administrator or a security guard that an infraction has
occurred. Whenever an intrusion occurs off the business hours, an
alarm is automatically transmitted to a central monitoring station
which will apply the predetermined official arrangements provided
by the owner of the fleet.
[0036] Whenever a high level disturbance, such as a disconnecting
of the VSU or the car battery (detected by the voltage drop
detector) or tilt detection, occurs in the armed or in the disarmed
mode, an alarm is automatically set by the master unit.
[0037] Accordingly, the VSU waits for a disturbance event or a key
reading event in 520. At 522, if no event is received, the VSU
continues to wait (in 520) and if an event is received, in 524, a
corresponding event message is sent and the communication link is
opened to wait for a command. In 526, if a command is received from
the master unit; in 530, the VSU executes the command and goes to
the prescribed mode. A timer T4a is then reset in 528. Timer T4a
manages the deactivation time period during which no alarm flag is
set to provide a deactivation time for the potentially authorized
user to show its security key. If no command is received; in 532,
it is checked whether the deactivation time (T4a) has lapsed. At
534, if the deactivation time has not lapsed and an event is
received; in step 536, the VSU sends a corresponding event message
and opens the communication link with the master unit to wait for a
command. In 538, if a command is received from the master unit; in
540, the VSU executes the command and goes to the mode prescribed
by the command. If no command is received, the VSU continues to
wait for the end of timer T4a in 532.
[0038] In 532, if the deactivation time has lapsed, either no
security key has been shown or the security key shown was invalid.
The VSU then waits for the next command from the master unit in
542. At this time, a command to activate the alarm indicator 42
(see FIG. 2), for example, can be received, but the VSU takes no
action until it receives the appropriate command from the master
unit. In 544, if no command is received; in 548, the VSU tries
again to communicate with the master unit. In 550, if a command is
received; the VSU executes that command in 552. If still no command
is received, in 554, the VSU is most probably out of the zone
covered by the master unit (out of range), i.e. an authorized user
is currently out with the vehicle, and no command can be received
from the master unit. In this case, the VSU should stop sending
event messages over and over in order to save electrical energy.
Accordingly, in 554, it goes back to the beginning of the armed
mode.
[0039] Furthermore, during the armed mode 514 and in parallel to
steps 520 to 554, a timer T6 is used in managing the transmission
of presence messages to the master unit for inventory purposes. In
step 516, timer T6 is reset and the VSU waits until the end of the
duration of T6. Timer T6 typically lasts five minutes but the
duration of T6 may be reprogrammed by the master unit. At the end
of the duration of T6, step 518, the VSU opens the communication
link with the master unit and sends a presence message. It then
goes back to step 516.
[0040] It is noted that a case where the vehicle is out with an
authorized user and the armed mode is activated can arise in a
particular circumstance wherein the authorized user has parked the
vehicle for a short period of time, for having a lunch in a
restaurant for example. The VSU automatically resets after thirty
seconds of inactivity (defined by timer T3), as will be discussed
further below, and then goes into the armed mode. As the VSU should
rather be in the disarmed mode, if communication with the master
unit is lost, it goes back in that mode. Alternatively, the VSU may
have an out-of-range mode wherein it stops to send event messages
but still try to communicate with the master unit each five minutes
or so, i.e. as prescribed by timer T6.
[0041] It is contemplated that the VSU is a slave responding to the
master unit and that the VSU takes no action and makes no decision.
It only listens to commands received by the master unit. The master
unit only decides that a valid key has been read and that the VSU
should go into the disarmed or the maintenance mode.
[0042] It is noted that the VSU only opens the communication link
between the VSU and the master unit. It opens the communication
link, i.e. it sends an open link message to the master units and
waits for a command, only at given prescribed times. The VSU opens
the communication link every five minutes (or any other time
prescribed by timer T6), at the time it sends a presence message
(step 518). It also opens the communication link each time an event
message is being sent (steps 524, 536, 542 and 548).
[0043] FIG. 6 illustrates the disarmed mode of the VSU. This mode
allows an authorized user to use the vehicle and exit the parking
lot, for a car trial with a potential buyer for example, or to go
in the car to get any object left in the vehicle. The VSU typically
goes into the disarmed mode on a command from the master unit. When
the master unit determines that a valid security key has been
presented to the security key reader, it sends a command to the VSU
to go in the disarmed mode. When in disarmed mode, the VSU stops
sending event messages to the master unit in response to low level
disturbance events. However, if a high level disturbance event
occurs, an event message is sent accordingly. In order to provide a
condition for rearming the security system when an authorized user
returns the vehicle to the parking lot, the VSU automatically
resets after thirty seconds of inactivity, i.e. the activation time
period prescribed by a timer T3. More specifically, if no
disturbance event and no key reading event arises for thirty
seconds, the VSU automatically goes into the reset mode.
[0044] Accordingly, the disarmed mode starts in step 610. In 612,
timer T3 is reset. In 614, if timer T3 has lapsed, i.e. no event
occurred for thirty seconds, the VSU resets, in 616. As described
along with FIG. 5, the VSU will then go in the armed mode. If, in
614, timer T3 has not lapsed; in 618, if no event arises, the VSU
still waits for timer T3 to lapse in 614. A low level disturbance
event resets timer T3 in 612. If a high level disturbance event
occurs, in 620, the VSU sends an event message to the master unit
and opens the communication link to wait for a command. In 622, if
a command is received; in 624, the command is executed and the VSU
then goes in the mode prescribed by the command. If, in 622, no
command is received; in 612, timer T3 is reset and the disarmed
mode goes on.
[0045] FIG. 7 illustrates the maintenance mode of the VSU. The
maintenance mode allows a technician to do maintenance and repair
activities on the vehicle. This mode allows a technician to remove
the battery from the vehicle, to replace it for example, or to
disconnect the VSU without initiating an alarm. Furthermore, in
opposition with the disarmed mode, the VSU will not be rearmed
after thirty seconds of inactivity. It will rather be rearmed
automatically after one hour (provided by a timer T2) and thereby
provides the technician with one hour for doing the task to be
done. The maintenance mode is activated by showing an appropriate
security key to the security key reader while the VSU is in the
armed mode. Accordingly, there are two levels of security keys,
technician security keys and authorized user security keys. When a
security key is shown to the VSU, the master unit receives the key
identification code and, according to the code received, it
determines which mode should be activated. When in maintenance
mode, the technician can reactivate the armed mode by showing its
security key to the security key reader. The master unit then
commands the VSU to go to the disarmed mode and the armed mode will
be reactivated after thirty seconds of inactivity.
[0046] Accordingly, the maintenance mode starts in step 710. In
712, timer T2, which defines the inactivity time period before the
VSU is to be rearmed, is reset. In 714, if timer T2 has lapsed; the
VSU goes into the disarmed mode (see FIG. 6) in 716 and will
consequently wait for another thirty seconds of inactivity (as
prescribed by timer T3) before it resets and then goes into the
armed mode. If, in 714, timer T2 has not lapsed; the timer will go
on until a key event occurs. In 718, if a key event occurs; in 720,
the VSU send a key reading event message according to the key read
and then waits for a command from the master unit. In 722, if a
command is received; in 724, it is executed and the VSU goes into
the mode prescribed by the command. In 722, if no command is
received, the maintenance mode goes on. It is noted that, in 716,
the VSU could rather go into the reset mode.
[0047] The master unit receives event messages, i.e. disturbance
event messages and key reading messages, or presence messages from
the VSUs. Each time a message is received, the appropriate action
is undertaken. FIG. 8 illustrates the behavior of the master unit
as an event message is received, in step 810, from one of the VSUs.
In 812, the appropriate steps are undertaken depending on the
nature of the event message received, i.e. a low level disturbance
event, 814, a high level disturbance event, 816, or a security key
event, 818.
[0048] If the event is a low level disturbance event message, such
as a motion detection event message, the master unit waits for a
security key event message for a given deactivation time period
prescribed by timer T4b. This time period corresponds to timer T4a
of the VSUs, i.e. thirteen seconds. If no valid security key is
shown, an alarm flag is set. Accordingly, in step 820, timer T4b is
reset. In 822, if timer T4b has lapsed, i.e. no security key was
shown to the VSU and the deactivation time has lapsed, an alarm
flag is set in 834. Otherwise, the master unit waits for a security
key event message in 824. If a low level event message is received
during that time, nothing is done and the master unit continues to
wait for the security key event message. However, if a high level
event message, such as a tilt event message or a voltage drop event
message, is received during that time, an alarm is automatically
set in 834. Hopefully, in 824, a security key message is received
and the master unit validates the key identification code in its
database in 826. In 828, if the code happens to be invalid, an
alarm flag is set in 834. If the code is valid, it can be
associated with a normal authorized user or to a technician. In
830, the master unit waits for a communication link to be
established with the given VSU, since, as described hereinabove,
communications between the VSU and the master unit is to be
initiated by the VSU. In 832, the appropriate command is sent to
the VSU depending on the code read, i.e. if the code is associated
with a normal authorized user, the command prescribes the disarmed
mode but if the code is associated with a technician, the command
prescribes the maintenance mode to the VSU.
[0049] Whenever a high level disturbance event message is received,
816, an alarm flag is set in 834. The alarm flag typically
activates an alarm siren, an intercommunication system, a pager or
a central monitoring station as described hereinabove. In 836, the
master unit also waits for the communication link to be established
with the given VSU in order to, in 838, send a command to the VSU
to activate its alarm indicator. The master unit may also display
on a screen the type of event that generated the alarm along with
data regarding the associated vehicle such as its model, its color
and its location in the parking lot.
[0050] The master unit may also be connected to a network of video
cameras covering the parking lot. The location of the vehicle
associated with the alarm may be found using a local positioning
system installed in the VSU for example or, if the vehicle is to be
parked at a specific position in the parking lot, the location can
be retrieved from a database. The video camera covering the zone in
which the vehicle is located may then be selected and the video
image provided by the camera be displayed on a screen.
[0051] As discussed hereinabove, when the VSU is in maintenance
mode, the technician may activate the armed mode by showing its
security key to the VSU. Accordingly, in 818, if a security key
event message is received, the master unit validates the key
identification code in 840. In 842, if the code is a valid
technician code; in 844, the master unit waits for the
communication link to be established with the given VSU in order
to, in 846, send a command to the VSU prescribing the disarmed
mode. If, in 842, the code is not a valid technician code, an alarm
flag is set in 834.
[0052] FIG. 9 illustrates the behavior of the master unit as a
presence message is received from one of the VSUs. When a presence
message is received in 910, the presence is recorded in a database
in 912. The time at which the message is received and the vehicle
identification code are saved in the database. The master unit thus
keeps track of the vehicles present in the parking lot.
[0053] FIG. 10 illustrates how the master units checks for missing
vehicle periodically so that, if a vehicle is out for a period of
time that exceeds the allowable missing time period (typically one
hour), a missing warning is set to alert the appropriate person in
charge, the security guard or any suitable authority. Accordingly,
while the master unit waits for event messages, it also performs,
in parallel, an inventory check every five minutes, provided by a
timer T7. The process begins in 1010. In 1012, the master unit
waits for the missing time period prescribed by T7, i.e. five
minutes. In 1014, it then checks in the database whether one of the
VSU has been out, i.e. no presence message has been received, in
more than the allowable missing time period (one hour). In 1016, if
no vehicle is missing; in 1012, the master unit waits another five
minutes before doing the check again. If one vehicle of the fleet
is missing; in 1018, a warning flag is set.
[0054] It is noted that the flow chart provided in FIG. 5 to 10
have been simplified for ease of illustration and that some
features of the system that can be present or not are not
illustrated. For example, each time an alarm flag or a warning flag
is set, the flag is recorded into a database and the master unit
undertakes the suitable action to communicate the flag and the
appropriate information about the event that generated the flag, to
the appropriate authority.
[0055] For example, if an event is generated by the voltage drop
detector, the event may either be a high level voltage drop, i.e.
the VSU has been disconnected, or a low level voltage drop, i.e.
the battery level is decreasing below a predetermined level. The
first case automatically generates an alarm flag, which, if it
occurs off the business hours, is communicated to the central
monitoring system. The second case rather generates a low battery
level warning and no alarm flag is to be communicated to the
central monitoring system. This feature is used to monitor the
battery level of each vehicle and to detect a low battery level. If
a low battery level event is generated, a low battery level warning
is recorded by the central monitoring system, which indicates to a
vehicle fleet manager that an action should be undertaken soon in
order to avoid a situation where the battery reaches a level that
is critically low. Furthermore, each time an alarm flag is
communicated to the central monitoring system, information about
the event that generated the alarm is also communicated and
different actions may be carried on depending on the type of
events.
[0056] Furthermore, the database keeps a history of all events
occurring with respect to each vehicle. The master unit is thus
able to generate a warning if a specific vehicle has been taken for
use by an authorized user but the vehicle has now been out for a
long period of time (more than one day for example). The vehicle is
then considered as being missing. A warning then appears on the
master unit interface. The administrator may also be contacted.
[0057] While illustrated in the block diagrams as groups of
discrete components communicating with each other via distinct data
signal connections, it will be understood by those skilled in the
art that the preferred embodiments may be provided by a combination
of hardware and software components, with some components being
implemented by a given function or operation of a hardware or
software system, and many of the data paths illustrated being
implemented by data communication within a computer application or
operating system. The structure illustrated is thus provided for
efficiency of teaching the present preferred embodiment.
[0058] The embodiments of the invention described above are
intended to be exemplary only. The scope of the invention is
therefore intended to be limited solely by the scope of the
appended claims.
* * * * *